Q&A

Q: How to use the Temporal Artery Thermometer?

A: This is a step by step guide for using the TAT.

Do NOT push the Scan button before starting the measurement. This is not an on/off button

1. Brush hair aside if covering the (temporal artery) TA area. Place the probe flush on the center of the forehead.

2. Press the Scan button, keep pressed throughout measurement.

3. Slowly slide the probe midline across the forehead to the hair line in 2-3 seconds.

Do NOT scan over the hair with the TAT, brush hair aside before measuring.

Slide the thermometer straight across the forehead, not down the side of the face.

4. Scan behind the ear.

5. Release button, read and record.

Display will remain for 30 seconds, before automatic turn-off.
To turn off immediately, press and release.
To restart immediately, depress button and continue as above.

Q: Why the temporal artery?

A: The temporal artery area has a long history of temperature measurement, dating back to the early centuries before Christ with the first recorded references to palpation of the head for fever assessment. The temporal artery is a branch of the internal carotid artery, but courses within a millimeter or two of the skin's surface over the lateral forehead. It is readily accessible and, despite lying so close to the skin surface, presents no risk of injury from being touched. Since it is not an anastomosing vessel, the perfusion remains relatively constant, ensuring the stability of blood flow required for the AHB method.

Q: Why behind the ear?

A: Measuring the temperature behind the ear eliminates the possibility of false low temperature readings caused by the evaporative cooling effect of diaphoresis at the temporal artery. Vasodilation, which always precedes diaphoresis, also provides the area behind the ear with the high rate of perfusion required for accurate measurement. However, when vasodilation is not present, the perfusion rate behind the ear is too low and variable to give an accurate measurement. Other alternate areas when the head is inaccessible due to trauma or dressings include the neck and inguen.

Q: What is the technology?

A: Patented infrared technology has led to the development of small, durable, infrared scanners that calibrate the arterial heat balance (AHB). One sensor measures the arterial temperature on the patient's skin, capturing the peak reading, while another sensor measures ambient. Since ambient temperature has a direct effect on skin temperature, the thermometer automatically measures both many times per second — and uses a patented algorithm to automatically adjust the correct AHB equation.

Q: How is the cut-off for fever chosen?

A: 100.4°F (38.0°C) is the medically accepted definition of a fever for more than 100 years, is recommended by AAP, CDC and WHO, and used in every medical institution in the world.

Q: What types of thermometers are recommended for use in schools? For use by families?

A: Only those that are clinically accurate as demonstrated by published peer-reviewed clinical studies. For school nurses checking students that might be sick, a professional grade fast, accurate, non-invasive thermometer scanning the temporal artery with more than 100 published peer-reviewed clinical studies, is best. For families, a home model thermometer that is fast, accurate, and non-invasive, scanning the temporal artery, backed by more than 100 published peer-reviewed clinical studies, is best.

Q: What makes thermometers accurate? What should we know about thermometer accuracy?

A: Published peer-reviewed clinical studies. Without such studies by medical professionals, there is no assurance of accuracy on children and adults in all settings.

Accuracy specifications by manufacturers of thermometers are laboratory accuracy, not accuracy in actual use on people being tested for fever. Laboratory accuracy tests do not include important physiological effects which vary from person to person, and setting to setting, which can affect the actual accuracy well beyond their laboratory accuracy.

Published peer-reviewed clinical studies are the gold standard for accuracy, since they include actual use on people in many settings, which automatically includes the physiological effects that vary from person to person and setting to setting. Only these studies can provide the assurance that the thermometer will provide accuracy in detecting fevers for all ages in all settings.

With more than 100 published peer-reviewed clinical studies attesting to the accuracy on all ages from newborns to geriatrics, in all settings where fever detection is needed, the Exergen Temporal Artery Thermometer is by far the most proven accurate, compared to thermometers which have no or very few clinical studies.

Q: Are there any published studies on Circadian effects on fever?

A: YES, not one but three

Harding et al (2020). Fevers Are Rarest in the Morning: Could We Be Missing Infectious Disease Cases by Screening for Fever Then? Undergoing peer review at https://doi.org/10.1101/2020.05.23.20093484

Harding et al (2020). Fever incidence Is Much Lower in the Morning than the Evening: Boston and US National Triage Data. West J Emerg Med. 2020 Jun 24;21(4):909-917. doi: 10.5811/westjem.2020.3.45215. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7390559/

Harding et al (2019). The daily, weekly, and seasonal cycles of body temperature analyzed at large scale. Chronobiol Int. 2019 Dec;36(12):1646-1657. doi: 10.1080/07420528.2019.1663863. Epub 2019 Sep 17. https://publishingimages.s3.amazonaws.com/eZineImages/PracticePerfect/706/The_daily_weekly_and_seasonal_cycles_of_body_temperature.pdf